Process of making gas.



No. 650,698. Patented May 29, 1900. c. WHITFIELD.

PROCESS OF MAKING GAS.

Application filed Nov. 9,- 1899.

2 Sheets8hee( I.

(No Model.)

witnesses.

THE nonms PETERS 00,. PHOTO-LITHO-, WASHINGTON, n. c,

No. 650,698. Patented May 29, I900. C. WHITFIELD. PROCESS OF MAKING GAS.

(Application filed Nov. 9, 1899.)

2 Sheets-Sheet 2 t (No Model.)

Min ess es.

ma NORNS vzTzns co. PNOYO-L'XTHO" WASHINGTON, nv c.

PAT NT OFFICE.

CHARLES WHITFIELD, OF KETTERING, ENGLAND.

PROCESS oF MAKING eAs.

SPECIFICATION forming part of Letters latent No. 650,698, dated May 29, 1900.

Original application filed December 30,1897, Serial No. 664,777. Divided and this application filed November 9,1899. sear Na. 736,392. (No specimens.)

To CLZZ whom it may concern: v

I Be it known that 1, CHARLES WHITFIELD, a subject of the Queen of Great Britain and Ireland, residing at Kettering, in the county of Northampton, England, have invented Improvements in Processes of Making Gas, of which the following is a specification.

This invention has for its object the more. complete conversion of solid hydrocarbon compounds into the gaseous state than has been possible by the means heretofore in use; and the invention is designed for use with that class of apparatus which is employed for the generation of what are commonly known as producer-gas and water-gas.

It is well known that when carbonaceous fuel is burned With oxygen carbonic acid is produced and that when this compound is passed through a mass of incandescent carbon it is converted into carbonic oxid. When atmospheric air is used for supplying the oxygen for the combustion of the carbonaceous fuel and steam is added, the oxygen and hydrogen of which the latter is composed become dissociated, the oxygen thus liberated combining with some of the carbon, forming an additional supply of carbonic oxid. This additional supply of carbonic oxid and the dissociated hydrogen enrich the first products and reduce the percentage of diluent nitrogen in the resultant compound. Owing, however, to the cooling effect of the steam and carbonic acid on the incandescent fuel and to the fact that the conversion of carbonic acid into carbonic oxid can only be completely effected at a temperature of about 1,000 Fahrenheit, the amount of steam that can be treated in this way is limited by the amount of sensible heat (produced by the initial combination of the oxygen of the atmosphere with the carbonaceous fuel on the grate or near the twyers) which is available above that temperature. Also, as the heavier hydrocarbons are only converted into fixed gases when raised to a temperature somewhat above 1,000 Fahrenheit in contact with a further supply of oxygen or hydrogen, it becomes necessary to heat the vapors which are given off when the fuel is first placed in the generator or producer to or above that temperature. Now myinvention has reference to a method whereby vap- The process consists, first, in raising the fuel to a high temperature at or near the bot tom of the generator or producer by forcing air, either at ordinary temperatures or heated in any suitable Way, through the grate or twyers; secondly, in injecting into the fuel, at a point above the zone of combustion where the said fuelis in a state of incandescenc e and where its temperature is sufficiently high, as much steam as the heated fuel will decompose in view of the other work to be accomplished, and, thirdly, in causing the said steam to convey the condensable and distillation products of the fuel into the said incandescent fuel before the gaseous products pass ofi through the main outlet.

In order to carry out the above-described method, I employ apparatus of the kind described in another application for Letters Patent filed by me, dated December 30, 1897, Serial No. 664,777, of which this application is a division, and such as I shall now describe with reference to the accompanying drawings, in WhlCl1- Figure 1 represents a plan of the generator or producer. Figs. 2 and 3 are vertical sections taken on the lines X X and Y Y, respectively, of Fig. 1; and Fig. 4 is a horizontal section taken on the line Z Z of Fig. 3. Figs. 5 and 6 are similar views to Figs. 3 and 4:, respectively, showing a modified construction. At some distance-say one or two feetabove the grate or bottom A in the arrangement shown in Figs. 1 to 4, inclusive, there is provided a belt B, that extends more or less around the generator and is connected by openings 0 with the interior of the fuel-space just above the zone of combustion. The belt B is connected by a casing B and a pipe or conduit D with the top of the generator, where the fuel is admitted througha hopper F. Into the casing 13 projects a steam-nozzle E in such a manner that the steam issuing from the nozzle will induce a current of gas to flow from the upper part of the generator to the belt, so that the steam which is to be decomposed carries with it the volatile compounds to escape to the outlet G, which is placed at some distance-say two or three feet-from the top of the generator, without first passing through a mass of incandescent fuel at H, and there becoming decomposed or otherwise fixed.

I is an opening for the admission of air into the closed ash-pit below the fire-bars A from a blowing engine or fan.

J is a sight-hole for viewing the interior of the generator or producer when the same is at work, and K is an opening through which the generator or producer can be cleaned out when necessary. This opening is kept normally closed by a retort-lid P or other suitable air-tight door.

Instead of using a belt B, I sometimes, as shown in Figs. 5 and 6, connect the lower end of the downtake pipe or conduit D and branch pipe B by a conical nozzle B to an opening or passage L, which leads the steam and the volatile compounds from the upper part of the generator into the fuel at a point just above the zone of combustion.

It will now be understood that if air be passed through the mass of combustible fuel at the lower part M of the generator or pro ducer it will raise the fuel to a high temperature, and thereby produce combustion in the lower part of the fuel and produce and maintain incandescence in a mass of fuel at the part H above the zone of combustion, and that the green fuel at the upper part will be comparatively cool, but kept hot enough by the transmission of heat from the incandescent fuel below to give 0E volatile hydrocarbon compounds, which will be continually drawn away through the pipe or conduit D by the steam-jet E and delivered along with the steam into the incandescent fuel at the part H of the generator or producer just above the zone of combustion. These volatile hydrocarbon compounds and the steam are decomposed by the said incandescent fuel and pass off along with the carbonic oxid produced by the combustion of the fuel at the lower part of the furnace through the outlet from the outlet G be from tar and condensable products. I have obtained very satisfactory results'with a producer having a height of about twelve feet from the floor-level to the top of the fuel-chamber and an internal diameter of about two feet, the inlet or inlets G or L being about three feet above the grate A, the outlet G about eight feet above the grate, the pressure of the air supplied to the ash-pit being about equal to seven or eight inches of water, and the pressure of -steam admitted by the nozzle E being about seventy pounds per inch. With this data about one hundred and eighty pounds of coal can be burned per hour, yielding about thirteen thousand cubic feet of gas having a high calorific power.

The feeding of the fuel may be effected by hand or by any suitable automatically-acting apparatus, and where automatic apparatus is not employed the clinkering and pokering may be effected as in other generators or producers.

By carrying out the process as above described it is possible to utilize the heat produced by the initial combustion of a given Weight of fuel, first, for the production of carbonic oxid, and, secondly, for the decomposition of the greatest possible volume of steam and the fixing-of all the volatile hydrocarbons, whereby a compound containing the smallest percentage of diluent nitrogen, with a high percentage of carbonic oXid, hydrogen, and the lighter hydrocarbons,'is obtained, the volatile hydrocarbons being made to enrich what would be under ordinary circumstances only common producer-gas. Also the process enables cheap bituminous qualities of coal to verted into combustible gas in gas-producer in lieu of the more expensive anthracite and hard qualities of coal .which it has heretofore been necessary to use, and not only so, but enables a gas having a higher calorific power to be obtained than can be obtained in the usual way from such expensive fuels.

I am aware that it has heretofore been pro-' posed to introduce volatile compounds generated at the upper part of a gas-producer,- with or without steam, into the ash-pit or into the zone of combustion; but such process, which Ido not claim, differs, essentially, from mine, inasmuch as the resulting gas is altogether of a different and inferior quality to that obtained by my process.

What I claim is 1. The process of producing, combustible gas consisting in passing air only through the lower part of a mass of combustible fuel so as to raise the fuel to a high temperature, and thereby to produce combustion in the lower part of the fuel, and to produce and maintain incandescence in a mass of fuel above the zone of combustion, feeding green fuel on the top of the mass of fuel, injecting hydrocarbons distilled from said green fuel into the the freer will the gaseous products escaping be economically and advantageously con-' inass of incandescent fuel above the zone of combustion produced by the air, and withdrawing the resulting gaseous products from the mass of fuel at a pointbelow the green fuel at the top of the mass and the point where said hydrocarbons are injected, the mass of fuel above said zone of combustion being maintained at a gradually-decreasing temperature from this part to the top of said fuel.

2. The process of producing combustible gas consistin gin passing air through the lower part of a mass of combustible fuel so as to raise the fuel to a high temperature, and thereby to produce combustion in the lower part of the fuel, and to produce and maintain incandescence in amass of fuel above the zone of combustion, feeding green fuel on the top of the mass of fuel, withdrawing volatile compounds and products of distillation given off from the green fuel at the upperpart of said mass and injecting the same into the mass of incandescent fuel above the zone of combustion produced by the air, and leading off the gaseous products at a point between the zone of combustion'and the upper part of the mass of fuel, the mass of fuel above said zone of combustion being maintained at a graduallydecreasing temperature from this part to the top of said fuel, substantially as described.

3. The process of producing combustible gas consisting in passing air through the lower part of a mass of combustible fuel so as to raise the fuel to a high temperature, and thereby to produce combustion in the lower part of the fuel, and to produce and maintain incandescence in a mass of fuel above the zone of combustion, feeding green fuel on the top of the mass of fuel, withdrawing volatile compounds and products of distillation given oif from the green fuel at the upper part of said mass and injecting the same by means of steam into the mass of incandescent fuel at a point above the zone of combustion produced by the air, and leading oif the products of combustion of the fuel and the products of decomposition of the steam and volatile compounds and distillation products before they reach the upper part of the mass of green fuel from which said volatile compounds and distillation products are given off, the mass of fuel above said zone of combustion being maintained at a gradually-decreasing temperature from this part to the top of said fuel, substantially as described.

, Signed at Northampton, in the county of Northampton, in England, this th day of October, 1899.

CHARLES wnrrrmtn.

Witnesses:

A. M. TROUP, W. MAY. 

